Valvular disease
A. Generally, there are three types:
1. Stenosis—fibrotic, stiff, and thickened valves, resulting in reduced blood flow through the valve.

2. Regurgitation or valvular insufficiency— valves are unable to close completely, allowing blood to regurgitate.

3. Prolapse—“floppy” valves; may occur with or without regurgitation. The most common valvular defect.

ADRENOCORTICAL TUMORS

Functional adenomas are commonly associated with hyperaldosteronism and with Cushing syndrome, whereas a virilizing neoplasm is more likely to be a carcinoma. Determination of of the functional status of a tumor is based on clinical evaluation and measurement of the hormone or its metabolites. In other words, functional and nonfunctional adrenocortical neoplasms cannot be distinguished on the basis of morphologic features. 

Patholgical features
Adrenocortical adenomas

- They are generally small, 1 to 2 cm in diameter. 
- On cut surface, adenomas are usually yellow to yellow-brown due to presence of lipid within the neoplastic cells 
- Microscopically, adenomas are composed of cells similar to those populating the normal adrenal cortex. The nuclei tend to be small, although some degree of pleomorphism may be encountered even in benign lesions ("endocrine atypia"). The cytoplasm ranges from eosinophilic to vacuolated, depending on their lipid content. 

Adrenocortical carcinomas 

These are rare and may occur at any age, including in childhood.  
- Carcinomas are generally large, invasive lesions. 
- The cut surface is typically variegated and poorly demarcated with areas of necrosis, hemorrhage, and cystic change.
- Microscopically, they are composed of well-differentiated cells resembling those of cortical adenomas or bizarre, pleomorphic cells, which may be difficult to distinguish from those of an undifferentiated carcinoma metastatic to the adrenal.  

Acute tubular necrosis

Characterized by impaired kidney functions due to the destruction of the renal tubule epithelium.

Caused by a variety of conditions that lead to ischemia of the renal tubules, usually resulting from renal tubular injury or problems with vascular flow. It can also be induced by ingesting toxins or drug-related toxicity (e.g., gentamicin). 
The most common cause of acute renal failure.
Is a reversible condition, although it can be fatal.

Pyelonephritis

- A bacterial infection that affects the renal tubules, interstitium, and renal pelvis.
- One of the most common renal diseases. 
- Usually caused by gram-negative, rod-shaped bacteria that are part of the normal flora of the enteric tract. Most commonly caused by Escherichia coli, followed by Proteus, Klebsiella, and Enterobacter.
- The infecting bacteria are usually from the patient’s own enteric flora an example of an endogenous infection.
- Usually associated with a urinary tract infection (acute pyelonephritis) or involved with another precipitating condition, such as obstruction (chronic pyelonephritis).

Parathyroid hormone 

Parathyroid hormone (PTH) is a polypeptide (84 amino acid residues) secreted by the chief cells of the parathyroid glands (four glands: two in each of the superior and inferior lobes of the thyroid; total weight 120 mg).

The main action of PTH is to increase serum calcium and decrease serum phosphate.

Its actions are mediated by the bones and kidneys -
In bone, PTH stimulates osteoclastic bone resorption and inhibits osteoblastic bone deposition. The net effect is the release of calcium from bone.
In the kidney, PTH has the following effects:
- Increases calcium reabsorption.
- Decreases phosphate reabsorption.
- Increases 1-hydroxylation of 25-hydroxyvitamin D (i.e. activates vitamin D).

PTH also increases gastrointestinal calcium absorption. 

Bullous and Vesicular Disease
1. There are many diseases characterized by the presence of vesicles and bullae filled  fluid.
2. In pemphigus vulgaris, large, flaccid bullae filled with fluid occur on the skin and within the oral mucosa.
 - immunologic disease with IgG antibodies against the intercellular attachment sites between keratinocytes (type II hypersensitivity).
 - the vesicle in pemphigus vulgaris has a suprabasal location (just above the basal cell layer and resembling "tombstones")
 - scattered keratinocytes in the fluid as a result of acantholysis.
 - Nikolsky's sign is where the epidermis slips when touched with the finger.
 - fatal disease if left untreated (systemic corticosteroids)
3. Bullous pemphigoid is an immunologic vesicular disease whose vesicle are in a subepidermal location.
 - circulating IgG antibody against antigens in the basement membrane (type II hypersensitivity).
4. Dermatitis herpetiformis is an immunologic vesicular lesion characterized by the presence of IgA immune complexes (type III hypersensitivity) at the tips of the dermal papilla at the dermal/epidermal junction producing a subepidermal vesicle filled with neutrophils.
 - strong association with gluten-sensitive enteropathy, or celiac disease.